The Vickers 6-Ton (Mark E) Tank

One of the most significant tanks in the history of armoured weapons was the British light tank Vickers Mark E (Mk. E), also known as the Vickers 6-Ton. Paradocsically, it is also one of most forgotten tanks - apparently because it was used in combat by so-called minor countries only, and despite its origin, it is omitted in reviews of British WW2 tanks. However not appreciated by the British Army, the Vickers 6-Ton made an impressive international career. Despite a number of produced tanks was not big, but it was probably the most widespread tank type in the world before World War II, after Renault FT-17. Moreover, its licence gave birth to 12,000 tanks of the Soviet T-26 family and to the Polish 7TP tank.

A prototype of the Vickers-Armstrongs 6-Ton (Mark E) light tank was
constructed in 1928 in the British Vickers-Armstrongs Ltd factory, as a private venture. Among its designers, were famous John Carden and Vivian Loyd. The tank was designed in two variants: twin-turret Type A (Alternative A), armed with 2 machine guns only, and single-turret Type B (Alternative B). The novelty in the world was, that Type B tank was armed with a gun and a co-axial machine gun in a turret (called a "duplex mounting" at that time). Earlier tanks were either armed with only one weapon (like Renault family), or two weapons placed in different sides of turret, which could not be manned by one man at a time. The duplex mounting, which now seems obvious, allowed instant change between a gun or machine gun fire, depending on a target. Both weapons could have common sights as well. Thanks to two-men turret, the commander was not overloaded with tasks. With its short-barrel 47mm gun, Mark E Type B tank offered a good firepower, especially with HE shells, but also adequate to fight all contemporary tanks. Despite its armour showed later as unsatisfactory, at the moment of design it was even better, than of the British Medium Mk II tank. Mark E was also smaller and faster, than a Medium tank. The patented suspension was a new design, consisting of two independent sets of double bogies on each side, fitted with cantilever springs. Each suspension unit pivoted on its own axle. It was quite simple, reliable and offered a relatively smooth ride. Manganese steel tracks had a very good durability of 3000 miles.

The 6-ton tank was evaluated by the British Army but rejected. Apparently this was because the suspension was considered to be a weak element in the design.
On the other hand, this decision opened an export possiblity. Due to wide advertising, in 1930-1940 years these tanks were bought by (chronologically): USSR, Greece, Poland, Bolivia, Siam, Finland, Portugal, China and Bulgaria. Most of the exported tanks saw combat during their service.
Single tanks were also tested in several other coutries. Finally, a couple of tanks were found also in the British Army, because in 1939 the British Government took over four tanks Mk.E from the Thai order.
According to [2], Vickers works in Elswick manufactured 153 tanks Mark E. The USSR and Poland bought a licence to manufacture Vickers Mk.E. Basing on it, the USSR produced over 12,000 tanks of the T-26 family, while in Poland the 7TP tank was developed. Such a success resulted both from modern tank construction and Vickers efficient sales promotion.
However, in the early thirties, the tank was worth it. Despite more modern tanks were designed in the world from the mid-1930s, Vickers Mk. E retained a real combat value until the beginning of the WWII. Its 47mm gun, though obsolete, was still capable of destroying most of early-WWII tanks at a short distance, some at a medium distance. Only the armour of Vickers Mk.E showed completely insufficient due to a development of anti-tank guns.

The features of Vickers Mk.E, especially its suspension, had influence on many later world's tank designs, including Italian medium tanks from M-11/39 to P-40, and Czech tanks Skoda LT vz.35 (PzKpfw-35(t)) and T-21 (Hungarian Turan) - however, an opinion, that their suspension was copied from Vickers, is obviously false. Almost all tanks built after Vickers Mk.E adapted "duplex mounting" of weapons in one turret (it is noteworthy, that modern tanks also have all weapons and all crew members but a driver, in a turret - like Vickers Mk.E).

A confusion in designations:

An original factory designation was: Vickers-Armstrongs 6-Ton tank. The tank received also an export designation: Mark E (Mk. E in short; earlier Vickers export tanks were Mark C - one sold to Japan, and Mark D - one sold to Ireland). The most correct designation of twin-turret and single-turret variants is Mark E Alternative A or B (used in Vickers documents) or Type A / B. Therefore, designations: "Mark A", "Mark B", used in some publications are a result of misunderstanding and are incorrect. Also incorrect is a designation Mark F for this tank (see below). It should be noted, that the manufacturer's shortened designation: VAE, being a part of tanks' serial numbers, most likely comes from Vickers-Armstrongs Elswick.

A question of Mark F tank

A projected development of Mark E tank was the Mark F, developed in 1934 for Belgium. One of the Vickers Mk. E faults (revealed eg. in Poland) was its overheating and rather weak air-cooled engine Armstrong-Siddeley Puma. The original Mark E Type B tank had a turret offset to the left of the combat compartment, because on the right, there was a driver seat. In Mark F tank a new water-cooled engine Rolls-Royce Phantom II (125 HP?) was fitted. Because it would not fit at the back, where the old
Armstrong-Siddeley engine went, the engine in the Mark F was fitted on
the left side of the fighting compartment, which is why the turret had
to be moved to the right. Because of the driver's seat on the right, the turret was placed behind the driver, what demanded lengthening of the combat compartment. Only one prototype of the Mark F was built and tested in Belgium, but rejected.

However the Mark F didn't enter production, but late production Mark E tanks were fitted with such modified hull, retaining old Armstrong-Siddeley engine at the back. Therefore, they had a lengthened combat compartment, and part of them had the turret on the right, moved rearwards (tanks built for Finland). On the other hand, tanks built for Bulgaria and Siam had a lengthened combat compartment, but a turret on the left, in forward part. Sometimes they are called in publications: "Mark F", but this is not a correct designation of this variant.

As early as in 1928, there was an universal Vickers Medium Tractor designed on the Vickers 6-ton tank chassis. It was meant for military and civilian market as well. The British Army evaluated the tractor between 1930 and 1932, but finally rejected it. In 1934, Vickers developed an improved artillery tractor, powered by a stronger diesel engine. The British Army ordered 12 new tractors, with a designation: Dragon, Medium Mk.IV. They were given to one of heavy artillery regiments and used for towing 60-pdr guns (127 mm). In 1939, they were included into the British Expeditionary Force and sent to France, where they were seized by the Germans. Small series of artillery tractors were exported: in 1932 one vehicle was bought by the German company Siemens-Schuckert, in 1935 China bought 23 tractors and in 1937 India bought 18 tractors.

On the chassis of the artillery tractor Dragon, also a self-propelled anti-aircraft gun was developed (it was probably the first tracked armoured SPAAG in the world produced in series, although such guns were mounted on a wheeled armoured chassis before). 26 such vehicles were produced for Siam. The vehicle had an open superstructure, with 40mm Vickers automatic AA gun ("pom-pom") mounted, with a rate of fire 120 rds/min.

Artillery tractors, basing on a licensed Vickers 6-Ton chassis, were also developed and producedin the USSR (T-26T) and Poland (C7P). In the USSR, there was built a small series of tank bridgelayers ST-26 and 122 mm SP-howitzers SU-5 on T-26 chassis as well. Also several prototypes of SP-guns, armoured carriers and other special variants were designed.

For Vickers Mk.E tank, enginer N. Straussler designed a special trench-crossing gear. It was a lever device, which allowed tank to cross wide trenches. It was advertised by Vickers, but in practice it appeared very impractical and unsuccessful (photo - [3]).

A typical armament of the single-turret Type B was a short-barrel tank gun 47mm Vickers QF (Quick Firing), with a coaxial water-cooled 7.7mm Vickers machine gun. A telescopic sight was on the left side of the gun. Gun ammunition was 49-50 anti-tank and high explosive shells and there were about 4000-6000 rounds for MG.
- Finnish tanks were delivered without armament (see in part II).
- Polish tanks had 7.92mm wz.30 MG instead of Vickers MG.

Armour:

Construction:

The tank was of a classic construction, with a transmission compartment in front, combat compartment with turret or turrets in the middle, and an engine compartment in the rear. The hull was made of armour plates, riveted to a frame. The crew was three. The driver's seat was in front of the combat compartment, on the right side. Before the driver there was a large two-part hatch, with a vision slot (vision from the driver's seat in combat conditions was not very good). Vickers Mk.E Type A had two identical small one-man "dust-bin" turrets, each with a hatch above. In this variant, the commander-gunner and gunner were sitting on fabric belts. Type B had one big conical two-men turret. In tanks of the main production variant, the turet was offset to the left side. The tanks of the late production batches had hull with the turret offset to the right and to the rear, behind the driver. The commander and gunner both had their stations in the turret, which had a two-part hatch on the roof. Some tanks Type B had a turret with a rear niche for a radio Marconi (model SB4a?). In turrets' sides there were vision slots in the sides.